Telephone companies have provided, for a number of years, a call waiting service to which their customers may subscribe. If a customer subscribes to the call waiting service, then when the customer is on the telephone talking with a first party and a second party telephones them during the course of the conversation with the first party, then the customer will hear a beep in the earpiece of the telephone to alert them to the fact that another call is waiting. The customer can then transmit a flash hook to the telephone company's central office, placing the conversation with the first party on hold and connecting the customer with the second party, allowing the customer to then enter into a conversation with the second party. However, the customer has no way of knowing who the second party is when they hear the beep in the earpiece and they have no idea whether or not the call from the second party is sufficiently urgent to warrant interrupting the conversation with the fist party.
Newer methods for call delivery to a customer are or will soon be implemented. For example, the Integrated Services Digital Network (ISDN) will have digital signaling channels for notification of an attempt, on the part of the network, to deliver a call to a customer. With ISDN, a customer can be notified of the attempt to deliver the call even though the customer may be engaged in a telephone call or connection with another party. Such notification can be made at the customer's telephone station or at a separate terminal. Additionally, the customer can also receive information related to the second call, such as Calling Line IDentification (CLID). This information may be displayed on the customer's station. Given this information, i.e., the telephone number of the calling party, the customer may elect to put the call in progress on hold and to connect with the new call. Other options are also available, as is described, e.g., in the AT&T document 5ESS ISDN Basic Rate Interface Spec. 5E6 Software Release, the Bellcore "National ISDN-1" Document No. SR-NWT-001937, February 1991, the Bellcore "National ISDN-2" Document No. SR-NWT-002120, May 1992, and the AT&T document "5ESS Switch--The Premier Solution Feature Handbook" Document No. 235-390-500, dated September 1987, all of which are hereby incorporated herein by reference. However, ISDN does not allow the calling party to identify the urgency of their call or to provide the user with a notification initiated by and defined by the calling party.
The instant invention addresses the problems noted above by providing an Enhanced Call Waiting System which pre-screens the call from the second caller to determine a level of urgency before interrupting the customer advising that a call is waiting. The invention also includes means by which information regarding the new call can be communicated to the customer so that they can decide what action should be taken, if any.